equipment configuration

[MechDiver]

voop once bubbled...

However I do *not* agree that deco on a single tank is stupid. Far from. Many of my dives are on a single (big -- 18 l, 200 bar, 2 1.stages on an Y/H valve for redundancy) tank, and most of them are deco-dives. Not the WKPP-overnight-deco dives, but anywhere from a few minutes to 15-30 min deco or so. As a matter of fact, our std. dive tables include this form of deco-dives as well as NDL's.

All of us have our own ideas of what is safe and sane. Although you make good points, I think you need to include the posters training and experience level (mostly unknown), and the relatively isolated area for diving. The fact, as has been pointed out, that the question had to be asked also says something.

I would have to agree with boogie on this one.

MD

 

[voop]

MechDiver once bubbled...


All of us have our own ideas of what is safe and sane. Although you make good points, I think you need to include the posters training and experience level (mostly unknown), and the relatively isolated area for diving. The fact, as has been pointed out, that the question had to be asked also says something.

I would have to agree with boogie on this one.

MD

But, of course, I agree absolutely with what you say: training, experience and location means the world.

If I remember correctly, the poster has IANTD adv. nitrox training, and hence training (and possible experience too) in deco procedures. Hence, that was what I based my comments on.

I do not know the recompression facilities where the original poster is going atall. That does, of course, have influence on what risks one can accept too.

I just wanted to counter the chorus saying "dumb" -- it isn't necessarilly. Just like a dive within the NDLs can be "dumb" so can a deco dive -- if not being prudent and taking necessary precautions.

In the end, the only one who can decide what are the acceptable risks is "beche de mer" himself.

 

[cornfed]

Boogie711 once bubbled...

A) Prepare a will. Even if you don't have loved ones, it's always good to make sure your estate is in order and that your belongings won't end up in Probate.

B) Check your life insurance. Some policies won't pay for a diving accident, depending on circumstances. Make sure that when the inevitable 'big one' happens, at least your beneficiaries aren't going to get stiffed.

C) Clearly mark all your gear in LARGE letters. This helps recovery teams identify a body in low light or low visibility conditions.

D) Visit your local priest, Rabbi or Minister beforehand. Just to make sure you're at peace with all aspects of your life, both mental and spiritual, before you disembark.

E) Consider a pre-paid funeral. It often saves your loved ones from having to make decisions or come up with money in their time of grief.

F) Have fun! And remember - just because everyone is appalled you would consider such a trip, that doesn't make it wrong... it just means we can buy your gear for cheap from a grieving family.

ROFLMAO!

Maybe Santa will will bring us an :alert: "smilie".

 

[beche de mer]

MechDiver once bubbled...


The fact, as has been pointed out, that the question had to be asked also says something.

MD

The question didn't HAVE to be asked. I already have my own ideas. As I said, I was interested in people's views.

Now that the howls of opprobrium are receding, we are getting some intelligent discussion. Thanks for those who have provided some worthwhile input.

When I did my deep air course, 3 of the 4 people on the course were using a single tank with pony bottle. So doing deco dives with a single tank is not outrageous, in my view. Maybe you guys do things differently where your are.

Did someone suggest that a pony shouldn't be factored into gas calculations? So you ignore 20% of the gas you're carrying?

Diving with more than one buddy is sensible, and something we had discussed.

As far as gas consumption is concerned, well, anyone who has dived the tropics knows that when the water is warm and the visbility is good and things are well lit, consumption improves. Air consumption is something that would be determined during the coral dives.

Thanks to doc Intrepid for the link to the travel bands.

Finally, sometimes its not always possible to do it "by the numbers". You then have to decide whether to do it at all or let it pass. Not everyone has the resources to mount a "Dive the Titanic" expedition.

 

[beche de mer]

Oh. I forgot the disclaimer. "Don't try this at home kids!"

 

[pipedope]

Know what you are doing.

and

If you get yourself killed, don't come crying to me.

 

[kramynot2000]

Uncle Pug once bubbled...

Since you haven't told us and the information is coming out in drips and drabs... let me just assume that you will be using AL80s supplied by the dive operator.

Take a manifold and bands.

Or

Dive independent doubles.

Or

Dive an 80 on your back and sling an 80 stage to use first.

UP, I'm curious as to why you would want to use the slung stage first. Is it because you can ditch it when its empty in case of emergency and still have gas on your back?

 

[voop]

beche de mer once bubbled...


Did someone suggest that a pony shouldn't be factored into gas calculations? So you ignore 20% of the gas you're carrying?

Well, if I factor "that smaller bottle I sometimes bring along on my dives" into the gas calculations, I usually call it a "stage bottle" or "deco bottle" (and fill it with a rich Nitrox too).

Whatever you do, take care of yourself, and have a load of fun...

 

[Doc Intrepid]

is good. Your question revolves around a matter of definition(s):

Did someone suggest that a pony shouldn't be factored into gas calculations? So you ignore 20% of the gas you're carrying?

Perhaps "ignore" is not the right word. (And per one of your other observations, things may be different where you live.) In the US, while there is often confusion among many recreational divers, among technical divers the following definitions generally hold true:

A "decompression bottle" holds decompression gasses.

A "stage" bottle holds gas mixes that are used during various phases of a dive, often to preserve backgas. Stage bottles are breathed first because they are often either travel gas or, in the case of an emergency, may be jettisoned when empty. One attempts to retain one's true "emergency" gas on one's back, thus other gas supplies are breathed first.

A "pony" bottle is an imprecise term that is understood (defined) differently by different divers. Any word that is defined differently by different users results in its "true" definition being nearly meaningless.

Instead, the word "bailout" bottle is often used to identify a small tank of gas that is often used by recreational divers using single tanks while performing deeper dives. (A definitional problem all its own.) The idea behind having a redundant gas source is that if the diver suddenly experiences a catastrophic gas supply failure (for any reason)(and one's buddy is not immediately present), there is an unadulterated supply of gas available to return the diver safely to the surface.

The only way to ensure that the redundant gas supply is always available is to not plan to use it during the dive (unless an emergency occurs).

Therefore, while it may simply be an issue of semantics, divers who carry bailout bottles indeed do not plan the gas inside them as part of their routine gas planning. You perform your gas planning using backgas only. The bailout bottle is planned to allow the recreational diver to terminate the dive and conduct an emergency ascent at a 30 fpm rate, conduct safety stops, and safely surface afterwards. It doesn't factor into the dive plan as useable gas.

As Voop mentioned above, once you factor your slung gas into your gas planning its no longer a "pony" or "bailout" bottle. Its either a stage or a deco bottle, regardless of what size it is.

Hope this addresses your earlier question.

Doc

 

[Norm]

If you're going to do this, do what Pug said - dive an 80 and sling an 80. Take an extra reg, mask, and computer.